Ultrasound-Guided Repeated Saline Injections to Prevent and Treat Tendon Adhesions After Hand Tendon Repair

Scar tissue can form around a repaired tendon and restrict finger movement. This study will evaluate whether repeated ultrasound-guided normal saline injections, in addition to standard postoperative rehabilitation, can help prevent and treat tendon adhesion after surgical repair of zone II flexor tendon injuries. The study is a prospective, single-center, randomized controlled trial involving 80 adults aged 18 to 60 years with a zone II flexor tendon rupture in the index, middle, ring, or little finger. Participants will be assigned to one of two groups, with 40 participants in each group. Participants in both groups will receive the same standard postoperative rehabilitation treatment, including early active finger mobilization. In addition to this rehabilitation, the experimental group will receive ultrasound-guided percutaneous injections of 1 mL of normal saline at the tendon adhesion site on postoperative days 7, 14, and 21. The control group will receive standard postoperative rehabilitation alone, without postoperative normal saline injections. The primary outcome is total active motion of the repaired finger at 3 months after surgery. Finger movement, pain, hand function, postoperative finger infection, and tendon rupture will also be assessed at the scheduled follow-up visits.